Data/hora: 10/06/2024 06:31:36

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	22/10/2001	
Data da última atualização: 	22/10/2001	
Autoria: 	KANDA, K.; TAKAHASHI, M.; MIRANDA, C. H. B.	
Título: 	Nitrogen cycling agropastoral systems	
Ano de publicação: 	2001	
Fonte/Imprenta: 	In: KANNO, T.; MACEDO, M.C.M., ed. JIRCAS / EMBRAPA gado de corte international joint workshop on agropastoral system in South America. [Tsukuba]: JIRCAS, 2001.	
Páginas: 	p.75-84.	
Série: 	(JIRCAS Working Report, 19).	
Idioma: 	Inglês	
Notas: 	EMBRAPA-CNPGC and JIRCAS joint International Workshop on Agropastoral System in South America, held in Campo Grande, MS, Brazil, 1999.                                                                                                             	
Conteúdo: 	Agropastoral systems that combine soybeans and grass in a crop rotation have been proposed for sustaining grassland productivity in the low fertility soils of Brazilian Cerrados. We studied the nitrogen flow under an agropastoral system established in 1993 a Purple Red Latossol in Campo Grande, MS. Surface soil was collected from fields with continuous soybean cropping (6 years), soybeans cropped after 4 years of grassland, continuous grassland (6 years), grassland planted after 4 years of soybean cropping, a degraded grassland, and na original forest,; the samples were analyzed for N mineralization potential in the soil under the grasslands. The rate of N fixation in the soybeans was determined according to the N-difference method using a non-nodulating isoline, T201, as a control. The determined rate varied from 20 to about 50% of the total plant N. Most of the plant N  was harvested out with the grains, leaving a negative N balance in the field.It was determined that the amount of N entering the system through rain water was small. Nitrate accumulated from the surface to a depth of 100 cm in the soil under the soybeans, indicating a potential leachingof nitrate. The estimated amount of leaching from the soybean fields, whereas there was large compared with that from the grasslands. A large negative N balance was measured in the soybean fields, whereas there was a small negative N balance in the grassland fields.	
Palavras-Chave: 	Agropastoral systems; Ciclagem; Cycling; Sistema agropastoril.	
Thesagro: 	Cerrado; Nitrogênio.	
Thesaurus Nal: 	nitrogen.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CPAC - (12390-1) - ADD - PL - -- - CRI5532 -  - CRI5532 - DIS